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In Rust, constants are values that are bound to a name and are not allowed to change. Constants are always immutable and are declared using the const keyword. They must be annotated with their type, and they can be set only to a constant expression.

In this challenge, you will define and use a constant in Rust. This will help you understand how to declare constants and how they can be utilized in your programs.

Your task

  • Define a constant named MAX_SIZE with a value of 100.
  • Ensure that MAX_SIZE has the type i32.
  • Return the value of MAX_SIZE from the main function.


  • Use the const keyword to define the constant.
  • Ensure you specify the type of the constant explicitly.